How much electricity was consumed in Manchester during the 1950s? Planners at the Central Electricity Generating Board used this spectacular 3D model to record daily demand. It charts patterns of consumption over a period of two and a half years. The graph shows peaks in the winter and dips during warmer months.

The model consists of about three hundred cards with square-cut stepped edges in an enclosure of chrome steel uprights, mounted on a wooden base, with a handle at each end. Data represented from October 1951 to April 1954.